1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * sun8i-ss-cipher.c - hardware cryptographic offloader for
4   * Allwinner A80/A83T SoC
5   *
6   * Copyright (C) 2016-2019 Corentin LABBE <clabbe.montjoie@gmail.com>
7   *
8   * This file add support for AES cipher with 128,192,256 bits keysize in
9   * CBC and ECB mode.
10   *
11   * You could find a link for the datasheet in Documentation/arch/arm/sunxi.rst
12   */
13  
14  #include <linux/bottom_half.h>
15  #include <linux/crypto.h>
16  #include <linux/dma-mapping.h>
17  #include <linux/io.h>
18  #include <linux/pm_runtime.h>
19  #include <crypto/scatterwalk.h>
20  #include <crypto/internal/skcipher.h>
21  #include "sun8i-ss.h"
22  
sun8i_ss_need_fallback(struct skcipher_request * areq)23  static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
24  {
25  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
26  	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
27  	struct sun8i_ss_alg_template *algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher.base);
28  	struct scatterlist *in_sg = areq->src;
29  	struct scatterlist *out_sg = areq->dst;
30  	struct scatterlist *sg;
31  	unsigned int todo, len;
32  
33  	if (areq->cryptlen == 0 || areq->cryptlen % 16) {
34  		algt->stat_fb_len++;
35  		return true;
36  	}
37  
38  	if (sg_nents_for_len(areq->src, areq->cryptlen) > 8 ||
39  		sg_nents_for_len(areq->dst, areq->cryptlen) > 8) {
40  		algt->stat_fb_sgnum++;
41  		return true;
42  	}
43  
44  	len = areq->cryptlen;
45  	sg = areq->src;
46  	while (sg) {
47  		todo = min(len, sg->length);
48  		if ((todo % 16) != 0) {
49  			algt->stat_fb_sglen++;
50  			return true;
51  		}
52  		if (!IS_ALIGNED(sg->offset, 16)) {
53  			algt->stat_fb_align++;
54  			return true;
55  		}
56  		len -= todo;
57  		sg = sg_next(sg);
58  	}
59  	len = areq->cryptlen;
60  	sg = areq->dst;
61  	while (sg) {
62  		todo = min(len, sg->length);
63  		if ((todo % 16) != 0) {
64  			algt->stat_fb_sglen++;
65  			return true;
66  		}
67  		if (!IS_ALIGNED(sg->offset, 16)) {
68  			algt->stat_fb_align++;
69  			return true;
70  		}
71  		len -= todo;
72  		sg = sg_next(sg);
73  	}
74  
75  	/* SS need same numbers of SG (with same length) for source and destination */
76  	in_sg = areq->src;
77  	out_sg = areq->dst;
78  	while (in_sg && out_sg) {
79  		if (in_sg->length != out_sg->length)
80  			return true;
81  		in_sg = sg_next(in_sg);
82  		out_sg = sg_next(out_sg);
83  	}
84  	if (in_sg || out_sg)
85  		return true;
86  	return false;
87  }
88  
sun8i_ss_cipher_fallback(struct skcipher_request * areq)89  static int sun8i_ss_cipher_fallback(struct skcipher_request *areq)
90  {
91  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
92  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
93  	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
94  	int err;
95  
96  	if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG)) {
97  		struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
98  		struct sun8i_ss_alg_template *algt __maybe_unused;
99  
100  		algt = container_of(alg, struct sun8i_ss_alg_template,
101  				    alg.skcipher.base);
102  
103  #ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
104  		algt->stat_fb++;
105  #endif
106  	}
107  
108  	skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
109  	skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
110  				      areq->base.complete, areq->base.data);
111  	skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
112  				   areq->cryptlen, areq->iv);
113  	if (rctx->op_dir & SS_DECRYPTION)
114  		err = crypto_skcipher_decrypt(&rctx->fallback_req);
115  	else
116  		err = crypto_skcipher_encrypt(&rctx->fallback_req);
117  	return err;
118  }
119  
sun8i_ss_setup_ivs(struct skcipher_request * areq)120  static int sun8i_ss_setup_ivs(struct skcipher_request *areq)
121  {
122  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
123  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
124  	struct sun8i_ss_dev *ss = op->ss;
125  	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
126  	struct scatterlist *sg = areq->src;
127  	unsigned int todo, offset;
128  	unsigned int len = areq->cryptlen;
129  	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
130  	struct sun8i_ss_flow *sf = &ss->flows[rctx->flow];
131  	int i = 0;
132  	dma_addr_t a;
133  	int err;
134  
135  	rctx->ivlen = ivsize;
136  	if (rctx->op_dir & SS_DECRYPTION) {
137  		offset = areq->cryptlen - ivsize;
138  		scatterwalk_map_and_copy(sf->biv, areq->src, offset,
139  					 ivsize, 0);
140  	}
141  
142  	/* we need to copy all IVs from source in case DMA is bi-directionnal */
143  	while (sg && len) {
144  		if (sg_dma_len(sg) == 0) {
145  			sg = sg_next(sg);
146  			continue;
147  		}
148  		if (i == 0)
149  			memcpy(sf->iv[0], areq->iv, ivsize);
150  		a = dma_map_single(ss->dev, sf->iv[i], ivsize, DMA_TO_DEVICE);
151  		if (dma_mapping_error(ss->dev, a)) {
152  			memzero_explicit(sf->iv[i], ivsize);
153  			dev_err(ss->dev, "Cannot DMA MAP IV\n");
154  			err = -EFAULT;
155  			goto dma_iv_error;
156  		}
157  		rctx->p_iv[i] = a;
158  		/* we need to setup all others IVs only in the decrypt way */
159  		if (rctx->op_dir == SS_ENCRYPTION)
160  			return 0;
161  		todo = min(len, sg_dma_len(sg));
162  		len -= todo;
163  		i++;
164  		if (i < MAX_SG) {
165  			offset = sg->length - ivsize;
166  			scatterwalk_map_and_copy(sf->iv[i], sg, offset, ivsize, 0);
167  		}
168  		rctx->niv = i;
169  		sg = sg_next(sg);
170  	}
171  
172  	return 0;
173  dma_iv_error:
174  	i--;
175  	while (i >= 0) {
176  		dma_unmap_single(ss->dev, rctx->p_iv[i], ivsize, DMA_TO_DEVICE);
177  		memzero_explicit(sf->iv[i], ivsize);
178  		i--;
179  	}
180  	return err;
181  }
182  
sun8i_ss_cipher(struct skcipher_request * areq)183  static int sun8i_ss_cipher(struct skcipher_request *areq)
184  {
185  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
186  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
187  	struct sun8i_ss_dev *ss = op->ss;
188  	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
189  	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
190  	struct sun8i_ss_alg_template *algt;
191  	struct sun8i_ss_flow *sf = &ss->flows[rctx->flow];
192  	struct scatterlist *sg;
193  	unsigned int todo, len, offset, ivsize;
194  	int nr_sgs = 0;
195  	int nr_sgd = 0;
196  	int err = 0;
197  	int nsgs = sg_nents_for_len(areq->src, areq->cryptlen);
198  	int nsgd = sg_nents_for_len(areq->dst, areq->cryptlen);
199  	int i;
200  
201  	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher.base);
202  
203  	dev_dbg(ss->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__,
204  		crypto_tfm_alg_name(areq->base.tfm),
205  		areq->cryptlen,
206  		rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm),
207  		op->keylen);
208  
209  #ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
210  	algt->stat_req++;
211  #endif
212  
213  	rctx->op_mode = ss->variant->op_mode[algt->ss_blockmode];
214  	rctx->method = ss->variant->alg_cipher[algt->ss_algo_id];
215  	rctx->keylen = op->keylen;
216  
217  	rctx->p_key = dma_map_single(ss->dev, op->key, op->keylen, DMA_TO_DEVICE);
218  	if (dma_mapping_error(ss->dev, rctx->p_key)) {
219  		dev_err(ss->dev, "Cannot DMA MAP KEY\n");
220  		err = -EFAULT;
221  		goto theend;
222  	}
223  
224  	ivsize = crypto_skcipher_ivsize(tfm);
225  	if (areq->iv && crypto_skcipher_ivsize(tfm) > 0) {
226  		err = sun8i_ss_setup_ivs(areq);
227  		if (err)
228  			goto theend_key;
229  	}
230  	if (areq->src == areq->dst) {
231  		nr_sgs = dma_map_sg(ss->dev, areq->src, nsgs, DMA_BIDIRECTIONAL);
232  		if (nr_sgs <= 0 || nr_sgs > 8) {
233  			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
234  			err = -EINVAL;
235  			goto theend_iv;
236  		}
237  		nr_sgd = nr_sgs;
238  	} else {
239  		nr_sgs = dma_map_sg(ss->dev, areq->src, nsgs, DMA_TO_DEVICE);
240  		if (nr_sgs <= 0 || nr_sgs > 8) {
241  			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
242  			err = -EINVAL;
243  			goto theend_iv;
244  		}
245  		nr_sgd = dma_map_sg(ss->dev, areq->dst, nsgd, DMA_FROM_DEVICE);
246  		if (nr_sgd <= 0 || nr_sgd > 8) {
247  			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgd);
248  			err = -EINVAL;
249  			goto theend_sgs;
250  		}
251  	}
252  
253  	len = areq->cryptlen;
254  	i = 0;
255  	sg = areq->src;
256  	while (i < nr_sgs && sg && len) {
257  		if (sg_dma_len(sg) == 0)
258  			goto sgs_next;
259  		rctx->t_src[i].addr = sg_dma_address(sg);
260  		todo = min(len, sg_dma_len(sg));
261  		rctx->t_src[i].len = todo / 4;
262  		dev_dbg(ss->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,
263  			areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);
264  		len -= todo;
265  		i++;
266  sgs_next:
267  		sg = sg_next(sg);
268  	}
269  	if (len > 0) {
270  		dev_err(ss->dev, "remaining len %d\n", len);
271  		err = -EINVAL;
272  		goto theend_sgs;
273  	}
274  
275  	len = areq->cryptlen;
276  	i = 0;
277  	sg = areq->dst;
278  	while (i < nr_sgd && sg && len) {
279  		if (sg_dma_len(sg) == 0)
280  			goto sgd_next;
281  		rctx->t_dst[i].addr = sg_dma_address(sg);
282  		todo = min(len, sg_dma_len(sg));
283  		rctx->t_dst[i].len = todo / 4;
284  		dev_dbg(ss->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,
285  			areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);
286  		len -= todo;
287  		i++;
288  sgd_next:
289  		sg = sg_next(sg);
290  	}
291  	if (len > 0) {
292  		dev_err(ss->dev, "remaining len %d\n", len);
293  		err = -EINVAL;
294  		goto theend_sgs;
295  	}
296  
297  	err = sun8i_ss_run_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));
298  
299  theend_sgs:
300  	if (areq->src == areq->dst) {
301  		dma_unmap_sg(ss->dev, areq->src, nsgs, DMA_BIDIRECTIONAL);
302  	} else {
303  		dma_unmap_sg(ss->dev, areq->src, nsgs, DMA_TO_DEVICE);
304  		dma_unmap_sg(ss->dev, areq->dst, nsgd, DMA_FROM_DEVICE);
305  	}
306  
307  theend_iv:
308  	if (areq->iv && ivsize > 0) {
309  		for (i = 0; i < rctx->niv; i++) {
310  			dma_unmap_single(ss->dev, rctx->p_iv[i], ivsize, DMA_TO_DEVICE);
311  			memzero_explicit(sf->iv[i], ivsize);
312  		}
313  
314  		offset = areq->cryptlen - ivsize;
315  		if (rctx->op_dir & SS_DECRYPTION) {
316  			memcpy(areq->iv, sf->biv, ivsize);
317  			memzero_explicit(sf->biv, ivsize);
318  		} else {
319  			scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
320  					ivsize, 0);
321  		}
322  	}
323  
324  theend_key:
325  	dma_unmap_single(ss->dev, rctx->p_key, op->keylen, DMA_TO_DEVICE);
326  
327  theend:
328  
329  	return err;
330  }
331  
sun8i_ss_handle_cipher_request(struct crypto_engine * engine,void * areq)332  int sun8i_ss_handle_cipher_request(struct crypto_engine *engine, void *areq)
333  {
334  	int err;
335  	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);
336  
337  	err = sun8i_ss_cipher(breq);
338  	local_bh_disable();
339  	crypto_finalize_skcipher_request(engine, breq, err);
340  	local_bh_enable();
341  
342  	return 0;
343  }
344  
sun8i_ss_skdecrypt(struct skcipher_request * areq)345  int sun8i_ss_skdecrypt(struct skcipher_request *areq)
346  {
347  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
348  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
349  	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
350  	struct crypto_engine *engine;
351  	int e;
352  
353  	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
354  	rctx->op_dir = SS_DECRYPTION;
355  
356  	if (sun8i_ss_need_fallback(areq))
357  		return sun8i_ss_cipher_fallback(areq);
358  
359  	e = sun8i_ss_get_engine_number(op->ss);
360  	engine = op->ss->flows[e].engine;
361  	rctx->flow = e;
362  
363  	return crypto_transfer_skcipher_request_to_engine(engine, areq);
364  }
365  
sun8i_ss_skencrypt(struct skcipher_request * areq)366  int sun8i_ss_skencrypt(struct skcipher_request *areq)
367  {
368  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
369  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
370  	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
371  	struct crypto_engine *engine;
372  	int e;
373  
374  	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
375  	rctx->op_dir = SS_ENCRYPTION;
376  
377  	if (sun8i_ss_need_fallback(areq))
378  		return sun8i_ss_cipher_fallback(areq);
379  
380  	e = sun8i_ss_get_engine_number(op->ss);
381  	engine = op->ss->flows[e].engine;
382  	rctx->flow = e;
383  
384  	return crypto_transfer_skcipher_request_to_engine(engine, areq);
385  }
386  
sun8i_ss_cipher_init(struct crypto_tfm * tfm)387  int sun8i_ss_cipher_init(struct crypto_tfm *tfm)
388  {
389  	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
390  	struct sun8i_ss_alg_template *algt;
391  	const char *name = crypto_tfm_alg_name(tfm);
392  	struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
393  	struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);
394  	int err;
395  
396  	memset(op, 0, sizeof(struct sun8i_cipher_tfm_ctx));
397  
398  	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher.base);
399  	op->ss = algt->ss;
400  
401  	op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
402  	if (IS_ERR(op->fallback_tfm)) {
403  		dev_err(op->ss->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
404  			name, PTR_ERR(op->fallback_tfm));
405  		return PTR_ERR(op->fallback_tfm);
406  	}
407  
408  	crypto_skcipher_set_reqsize(sktfm, sizeof(struct sun8i_cipher_req_ctx) +
409  				    crypto_skcipher_reqsize(op->fallback_tfm));
410  
411  	memcpy(algt->fbname,
412  	       crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm)),
413  	       CRYPTO_MAX_ALG_NAME);
414  
415  	err = pm_runtime_resume_and_get(op->ss->dev);
416  	if (err < 0) {
417  		dev_err(op->ss->dev, "pm error %d\n", err);
418  		goto error_pm;
419  	}
420  
421  	return 0;
422  error_pm:
423  	crypto_free_skcipher(op->fallback_tfm);
424  	return err;
425  }
426  
sun8i_ss_cipher_exit(struct crypto_tfm * tfm)427  void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)
428  {
429  	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
430  
431  	kfree_sensitive(op->key);
432  	crypto_free_skcipher(op->fallback_tfm);
433  	pm_runtime_put_sync(op->ss->dev);
434  }
435  
sun8i_ss_aes_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)436  int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
437  			unsigned int keylen)
438  {
439  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
440  	struct sun8i_ss_dev *ss = op->ss;
441  
442  	switch (keylen) {
443  	case 128 / 8:
444  		break;
445  	case 192 / 8:
446  		break;
447  	case 256 / 8:
448  		break;
449  	default:
450  		dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);
451  		return -EINVAL;
452  	}
453  	kfree_sensitive(op->key);
454  	op->keylen = keylen;
455  	op->key = kmemdup(key, keylen, GFP_KERNEL);
456  	if (!op->key)
457  		return -ENOMEM;
458  
459  	crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
460  	crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
461  
462  	return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
463  }
464  
sun8i_ss_des3_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)465  int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
466  			 unsigned int keylen)
467  {
468  	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
469  	struct sun8i_ss_dev *ss = op->ss;
470  
471  	if (unlikely(keylen != 3 * DES_KEY_SIZE)) {
472  		dev_dbg(ss->dev, "Invalid keylen %u\n", keylen);
473  		return -EINVAL;
474  	}
475  
476  	kfree_sensitive(op->key);
477  	op->keylen = keylen;
478  	op->key = kmemdup(key, keylen, GFP_KERNEL);
479  	if (!op->key)
480  		return -ENOMEM;
481  
482  	crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
483  	crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
484  
485  	return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
486  }
487